Mechanical stoker for locomotives.



D.F. CRAWFORD. v MECHANICAL STOKER FOR LOCOMOTIVBS.

APPLICATION FILED AUG.'5. 1907.

Patented DBC. 1, 1908."

4 SHEETS-SHEET 1` v mvern'on @Rf M l.' I L.

mmwwmmmm -l a@ n D.l F. CRAWFORD.

MECHANICAL STOKER FOR LOCOMOTIVBS.

' APPLICATION FILED AUG. 6, 1907.

`Patented Dec. 1, 1908.-

4 SHEETS-SHEET 2 D. P. GRAWPORD.- y MECHANICAL STOKER POR LOGOMOTIVES.

murmullos' FILED AUG. a., 1 90'1..

Patented Dec. 1, 1908. I

- SHEETS-sum1?" a.

' wrrnissss D. F. CRAWFORD. MECHANICAL STOKBR POR LoGoMoTIVEs.

APPLICATION FIQED AUG. 6. 1907.

Patented Dec; 1, 1908.

4 SHEETS-SHEET 4.

nin.:

f W/ i l l l l i Inn-icuii."

INVENTOR DAVID F. CRAWFORD, OF PITTSBURG, PENNSYLVANIA.

Speccation of Letters Patent.

MECHANICAL STOKER FOR LOCOMOTIYES.

Patented nec. 1, 1908.

Application lledugust 6, 1907. Serial No'. 387,297.

To all whom Lt may concern:

Beit known that I, Davie I". Cinuvrono, a citizen of the United States,residing at Pittsburg, in' the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inMechanical Stokcrs for Locomotives, of which the following is aspecification.

My invention relates to stolting mechanism for locomotives, and has forits primary objects; to provide an under-feed lstokerand grateconstructed to secure a proper distribution of fuel over the grate and aproper lateral spreading froml the edges of the central mass of fuel; toprovide a stoker of the type indicated, having an improved arrangementwhereby the supply of air to the furnace is augmented and propercombustion throughout the body of fuel on the grate secured; to providea construction wherein the fuel may be fed direct from the tender of thelocomotive to the grate; to provide a [construction wherein the feed ofthe stoker and the auxiliary draft to the furnace are automaticallycontrolled by the pressure in the boiler, and finally, to provide aStoker and grate suited to locomotive work and designed to voperateeffectively and economically under the widely varying and unfavorableconditions incident to locomotive work. One embodiment of the inventionis shown in the accompanying drawings,

whereinmechanism is employed.

Briefly stated, the apparatus comprises an under-feed means adapted toconduct the fuel from the tender to the central portion of the furnaceand heap it laterally and longitudinally over the grate, together withan end drop grate and means adapted to agitate the bed of fuel and breakun the edges. to promote a spreading thereof. The device also includesapparatus for supplying auxiliary draft inwardly along the edges of thefurnace, together with automatic controlling means for the auxiliaryblast, and automatic controlling means for th'efeeding mechanism.

Rcferringnow to the drawings and the general arrangement of parts, 1 isthe n'reiox, a limited portion only` of which is shown, Q is the tender,the front part only Iof which is indicated, 3 is the underfeed,

mechanism extending from the tender and through the center of thefurnace for supplying coal to the trough il. and heaping it l upon thegrate, are the side grates rotatably mounted for agitating the fuel, 6is the drop grate, 7 is th'eoperating engine for actuating the feedmechanism, 9 are the air injectors op fated from the boiler, forsupplying a draft, l() are the air chambers extending longitudinallyalong the inner edge of each of the side grates and discharging throughthe twyers 11 (Figure 3) for supplying draft to the mass of fuel lyingin the trough el, and 12 is the automatic governing means regulated bythe condition of the Asteam in the boiler, for controlling the amount ofdraft and the speed of the feed mechanism, which is shown in detail inFigure 4.

Any form o f underfced mechanism may be employed, but that shown ispreferably used, and comprises a series of oscillating feed members 13extending` across the bottom of the feedtrough, and provided with theconnecting rods 14, 15, 16, and 17, and motive power is supplied by'means of. the engine 7 whose connecting rod 18 engages the crank 19which is connected with one of the members 13 bymeans of the. link 20.In operating this portion of the device, coal is supplied to the devicefrom the tender. andis gradually carried along by virtue of theoscillation of the members 13. until the lfront portion 4t of the troughis filled with coal, and a further addition causes the inaterial tospread out laterally and longitudinally over the grates 5 and 6. Thegrates are, as most clearly indicated in Figure 3, of the rocking type,each side heilig provided with a downwardly projecting' arm Q1 engaginga connecting arm 22 extending` longitudinally through the furnace andyoperable from the cab. The rocking of these grates o breaks up the edgesof the mass of material from the center trough 4, and'provides for thesprea ding of such material over otherwise the surface of the coal cakesand after having moved out a slight. distance upon the grate 5 furthermovement is arrested and an inehicient operation results. The drop grate6, as shown, is of the rocking type, pivoted at the ends at 23, and isoperated from the crankshaft 2t 4connected to the grate by means of thelinks and operated by the handle 26. The movement of the side gratesalso serves to provide loose fuel for the drop grate, which Wouldotherwise be insutlicientlysupplied atits outer edges. The feed from theside grates to the drop grate is also assisted by reason of thevrearward inclination ofthe side'grates'as indicated in Figure l. Theinclination of the side grates serves alsoanother function, in that thisinclination in connection with the non-inclination of the bottom of thefeed trough give a' trough of increasing capacity from the rear of thefurnacevto the front thereof, which is desirable, as the amount of fuelwhich must be carried increases from the rear to the front.

rl`he means for providing auxiliary draft also constitutes a feature ofmy invention, and Willnow be described in detail. EX- tending alongeither side of the trough 4 and across the front end of the furnace, isthe air chamber 10' (Figures l and Theends of this chamber are suppliedWith air pressure by means of the air injectors heretofore referred to,the steam for the injectors being supplied from the boiler by means' ofthe pipe 27. The upper side of this air chamber 10 is connected with thetwyers 1l having their openings directed transversely of the trough 4,whereby a thorough combustion at the center of the furnace is secured.The twyers may be of lany desired form, but I preferablyconstruct-themas indicated,.removably engaging the edge of the trough 4 on one sideand the supporting bars 28 on the other side. The automatic regulatingmeans shown in Figure 4 is employed for regulating the speed ofthe f eedoperating mechanism and the amount of blast, which regulating means isgoverned by the pressure of connected to the boiler, the pipe 3lprovides steam for operating the injectors 9, and the pipe 32 suppliessteam for operating the engine 7 Which controls the feed of the coal.Valves 33 and 34 are provided for controlling the flow of steam to thepipes 3l and 32, and these valves are operated by the diaphragm 35located in the casing 36. The spring 37 is provided for moving thediaphragm to its reverse position. Vhen the locomotive is not'workingthe pressure in the boiler of.

course rises, carrying the diaphragm to the employed,

the steam in the boiler- As here' shown, the pipes 29 and 30 areposition shown, cutting oill steam from the pipes 3l and 32., checkingthe feed of coal to the furnace, and cutting 0E the auxiliary blast.When the locomotive starts, the pressure on the left hand side of thediaphragm is of course decreased, permitting the spring 37 to move thevalves 33 and 34 to the left, opening the pipes 31 4and 32, and startingthe coal-feeding mechanism and the blast. In order that the blast may bestarted slightly in advance of the operation of the coal feedingmechanism, a slip connection comprising a pin 37 working in a slot 38isthe pin 37 being carried on a rod secured to the valve 34, which rodtele* scopes in the cylindrical projection from the valve 33 carryingthe slot 38. The amount of Valve opening to the pipes 31 and 32 isregulated by the pressure in the boiler, and the blast and the feed ofthe coal adjust themselves automatically in proportion to the amount ofsteam being used.

In lFigure 5 I have shown'an arrangement for supplying 'auxiliary blast.1n this form of apparatus each of the tvvyers 11 is supplied With anozzle 9 .as a substitute for the, injectors 9 at the ends' of the airchambers v as shown in Figure 2. By this arrangement y the injectorslivork directly to the f ire in` stead of generating pressure in achamber which subsequently discharges it to'the tire, and this modifiedform is more efhcient than the form irstdescribed. y

It will be seen from the foregoing that the type of stoker employedis'readily adapt` ed to a locomotive fire-box, that byl its use the coalemployed is easily carried from thev tender to the furnace Withoutliandling, and that'the location of the Stoker is advantageous in thatit is underneath the doorv of. the cab and out ofthe way, and further,that it interferes in no Way With the fire-door 39 (see Figure l).Therocking grates 5 provide for a proper spreading of fuel .over theentire furnace, and insure efficient service from all of the gratesurface. It Will be understood that the term locomotive re-boxas used inthe claims comprehends the use. therewithof the ordinary draft means assel cured by the exhaust'to the stack, which draft acts particularly .onthose parts of the tire to which the auxiliary draft is not directed.The arrangement of the auxiliary means the draft is applied in the mostadvantageous and economical manner.

It will be understood that my invention is not limited to the preciseform of device shown, as, if desired, some other form of feeding devicethan the one shown might be employed successfully, and other meansemployedfor agitating the coal on the Iside.

grates 5. So far as this latter feature is concerned, my inventioncontemplates broadly the use ofany means which will break up the body ofcoal upon the grate and permit it to spread. The auxiliary draft meanswhile described as operated by live steam from the boiler, need notnecessarily be so operated, as exhaust steam from the stoker engine, thepump, and even the locomotive cylinders, m1ght be utilized, andmyinvention comprehends the use of steam from any source Whatever. Ifdesired, the automatic control can be regulated by the temperature ofthe steam instead of the pressure, my invention" contemplating the usebroadly of any means whatever for controlling the 0peration of the coalfeed and the draft by g boiler.

meansfofthe condition of the steam in the Having thus describedmylinvention and `illustrated its use, what I claim as new and A desireto secure by Letters Patent, is 'the following:

l. In'a locomotive furnace, the combination with a locomotive fire boX,of an underfeed mechanism extending into the furnace, j a' grate at thesidethereof adaptedto receive the fuel supplied by the underfeedmechanism, and a drop grate extending across thev end of thegside grateand the underfeed mechanism, the furnace being so' constructed as tobreak up the outer edge of the body of fuel on the slde grate. l l

2. The combination witha locomotive fire- ,box, of an under-feedmechanism .extending longitudinally therethrough, side grates inposition to receive the lateral discharge from the feed mechanism, and aseries of inwardly directed air passages arranged along the edges of thegrates and'each provided with a steam jet for supplying draft. A

3. In a locomotive furnace, the combination with a locomotlve lire-box,of an under- 4feed mechanism extending into the furnace,

a graite at the sidethereof sloping downfurnace being sov constructed asto break up the outer edge of the body of fuel on the side grate.

4. In a locomotive furnace, the comb1nation with a locomotive fire-box,of an under 55 feed mechanism extending into the furnace, a grate at theside thereof adapted to receive the fuel supplied by theunderfeed'mechan ism, and a grate extendin across the end of the sidegratetand the un erfeed mechanism 0 Vand having a drop portion, thefurnace being so constructed as to break up the outer edge of thebody'of fuel on the side grate. 5. The combination with a locomotiverebox, of an under-feed mechanism extending longitudinally therethrough,side grates in' position to receive the lateral discharge from the feedmechanism, auxiliary means `for vsupplying blast to the furnace,fandautomatic means governed by the condition of the steam in the boiler,for controlling the speed of operation of the under-feed mechanism andthe blast, and adapted when the pressure in the boiler decreases tofirst increase the blast and then the feed. f 1

In testimony whereof 'I have hereunto signed my name in the presence ofthe sub- Vscribed Witnesses.

, DAVID F. CRAXVFORD. Witnesses.: J. C, BRADLEY,

ARoHWoRTH MARTIN.

